Since a group III-V compound semiconductor grown on an InP substrate has a band gap energy corresponding to the near-infrared region, photodetectors for communication, analysis, night photography; and the like, adopting such a group III-V compound semiconductor, have been studied and developed.
Non-Patent Literature 1 discloses a sample of a photodetector including an InGaAs/GaAsSb type II MQW absorption layer on an InP substrate. This photodetector has a cutoff wavelength of 2.39 μm. Spectral sensitivity characteristics at wavelengths from 1.7 μm to 2.7 μm are shown.
Meanwhile, Non-Patent Literature 2 discloses spectral sensitivities at wavelengths from 1 μm to 3 μm (temperature: 200 K, 250 K, 295K) of a photodetector including InGaAs/GaAsSb type II MQW on an InP substrate. In this photodetector, InGaAs and GaAsSb each have a thickness of 5 nm, and 150 pairs of InGaAs and GaAsSb are stacked. The photodetector has a cutoff frequency of 2.3 μm.